1. Field of the Invention
This invention relates to systems and processes for cleansing storm water, such as that which is created by storm runoff from streets, highways, parking lots and other paved surfaces into drainage systems in major urban areas.
2. Description of the Related Technology
Storm water that is created by storm runoff in heavily developed areas is typically channeled into storm drainage systems that eventually drain into nearby streams, creeks, rivers or other bodies of water. Unfortunately, paved surfaces that bear automobile traffic typically become coated with significant pollutants such as heavy metals and volatile organic compounds, both under normal traffic conditions and in particular when motor vehicle accidents occur. When normal rain or snowfall occurs, these pollutants tend to be swept away with the runoff storm water and eventually lead to contamination of the bodies of water that eventually receive them. Such contamination has become a significant environmental issue in many areas. In addition, a significant amount of debris such as bottles and cans tends to be swept away by storm water runoff.
Systems exist for filtering storm water runoff that are effective in removing debris from storm water and in removing certain other pollutants, such as hydrocarbons. For example, U.S. Pat. No. 6,080,307 discloses a storm drain insert that contains one basket for the collection of debris as well as a canister that contains a hydrophobic, compliant, oil-absorbent copolymer material that is said to be effective in removing oil from the storm water.
Unfortunately, prior to this invention no system or process has been developed that is capable of removing heavy metals from storm water in situ within a storm water drainage system. Technology exists for removing heavy metals from storm water within complex storm water treatment facilities, but not locally within storm water drainage systems where such treatment facilities are not present.
A need exists for an improved system and process for processing storm water that is effective in removing heavy metals, as well as hydrocarbons and other volatile organic compounds, from the storm water in situ within a storm water drainage system.